Gradual weight loss does not reduce the amount or rate of weight regain compared with losing weight quickly, a study says. Substantial weight loss is more likely to be achieved if undertaken rapidly, it pointed out. “Our results show that an obese person is more likely to achieve a weight loss target of 12.5 percent weight loss, and less likely to drop out of their weight loss program, if losing weight is done quickly,” said Katrina Purcell from the University of Melbourne who is also a dietitian.

The trial included 200 obese adults who were randomly assigned to either a 12-week rapid weight loss program on a very-low-calorie diet or a 36-week gradual weight-loss program based on current dietary recommendations. The initial rate of weight loss did not affect the amount or rate of weight regain: with similar amounts of weight regained by three years by participants on both diet programs who completed both phases of the study (around 71 percent in both groups), the team found.

This may impact the worldwide treatment of obesity, as global guidelines recommended gradual weight loss for the treatment of obesity, reflecting the widely-held belief that fast weight loss is more quickly regained, the study said. A number of possible explanations have been put forward for their findings, including that the limited carbohydrate intake of very-lowcalorie diets promotes greater satiety, and less food intake by inducing the production of hunger suppressants called ketones. Losing weight quickly may also motivate participants to stick to the diet, the authors said.

The study highlights the urgent need for committees that develop clinical guidelines for the management of obesity to change their advice, concluded Joseph Proietto, professor of medicine in University of Melbourne.